Automatic toaster



Nov, 29; 1938. M. H.-GRAHAM r 2,133,674

AUTOMATIC 'rAs'rER' Original Filed March 24, 1932 4 Sheets-Sheet 1INVENTOR MAURICE H- GRAHAM W24 6 4mm Nov. 29, 1938. M. H. GRAHAM2,138,574

' AUTOMATIC TOASTER I Original Filed March 24, 1932 I 4 Sheets-Sheet 212 v 7 III-J59...

MAdnmi: H. GRAHAM ATTORNEYS iNvchh'o n Nov. 29, 1938. M. H. GRAHAMAUTOMATICTOASTER Original Filed March 24, 1932 4 Sheets-Sheet 5 R wM MmN w E H T m m W6 M M R l u A M M Naw 29, 1938, M. H; GRAHAM AUTOMATIC'IOAS'IZER Ofiginal Filed March 24, 1932 4-Sheets-Sheet 4 INVENTOR H.GRAHAM A'r-romv'sys 'MAQHIGE I Patented Nov. 29, 1938 UNITED- STTESPATENT OFFICE AUTOMATIC roas'ma Continuation of application Serial No.600,913, March 24, 1932. This application March 13, 1933, Serial No.660,574

31 Claims.

This is a. continuation of my co-pending application Serial No. 600,913,filed March 24, 1932.

The present invention concerns itself with toasters and moreparticularly with bread toasters which are automatically operative tocontrol the toasting operation.

Various types of automatic toasters have heretofore been proposed. Onetype includes a clock mechanism with manual means for regulating thesame but it is diillcult or impossible to obtain uniform toast with itsince the oven temperature varies greatly with successive toastingoperations and varying time intervals therebetween. In other types ofautomatic toasters the surface temperature of the bread, its moisturecontent, and/or its interior temperature have been" utilized to controlor time the toasting operation.

Again, a type of toaster has been proposed wherein the action of a.clockwork or other timing mechanism serving to terminate thetoasting ofbread slices is automatically controlled or regulated by means of athermally responsive device afi'ected by-oven temperature, audit is withsuch general type of automatic toaster that this invention is morespecifically concerned." Previous toasters of tliis-type'have not beensuccessful because of the fact-that they will not produce uniform toastduring operation in which there are varying time intervals between suc-'cessive toasting operations.

It is a broad purpose of this invention to produce a thermostaticallycontrolled automatic toaster which will be operative to producesubstantially uniform toast irrespective .of the temperature of thetoasting space within the oven oi the toaster at the start of any giventoasting operation, and irrespective of the duration of the timeintervals between successive toasting operations.

More specifically, it is a purpose of the invention to provide animproved automatic toaster having thermally responsive timing meansincludinga temperature responsive member ailecting the time periodprovided thereby, which member is subject to the heat of the toasterheating elements and is so located that substantially uniform toastingof successive bread slices in the toaster results.

Also, the invention contemplates an improved automatic toaster providedwith timing means including a thermally responsive member affecting thetime period provided by the timing means, which member is subject to theheat of the toaster elements and is located so as to be traversed by anappreciable amount of convection currents produced by the toasterheating means and flowing in a predetermined path, preferably the maindraft of an upright oven type toaster passing through the toastingspace.

While the invention is not limited thereto in its broader aspects, thepreferred form of toaster contemplated by this invention and hereinillustrated and described, is an upright oven type of toaster under thecontrol 01' thermally responsive timing means comprising in this case avariable speed timer and a regulating thermostat directly exposed to,the radiant heat of the heating elements and located in the main airdraft passing" through the toasting space.

The above features of the invention and van-' with its lower guardplateremoved;'

Figure 3 is a longitudinal the line 33 of Figure 4; v

Figure 4 is a transverse cross section along the line |-4 of Figure 3; Ic

Figure 5 is an end view of the timing mecha- Figure 6 is a. sideelevation mechanism; a

Figure 7 is a cross section along the line of Figure 5, the oscillatorbeing shown adjusted into position to speed up-the timing mechanis andthus shorten the period of operation;

Figure 8 is a fragmentary view along the lines of Figure 7, theoscillator being shown adjusted to decrease the speed of the mechanismand thereby increase the period of operation;

Figure 9 is a fragmentary view showing a cross section along the line9-9 of Figure 4; and Fig. 10 is a view of the toaster in frontelevation;

some parts being broken away.

Referring more particularly'to the drawings, there is shown anautomatictoaster having a base member 4 formed oi stamped sheet metaland having an outer casingge'nerally designated by 6 mounted thereon.Within the casing 6, which is also formed of stamped sheet metal, thereare arranged a pair of heating elements 8 between which bread slices tobe toasted are cross section along y of the timing ures to 9, and fordepressing the bread carrier ill. The specific structures will not bedescribed in detail inasmuch as they form no part of the presentinvention and are fully described in the pending patent application ofMurray Ireland, entitled Toaster, Serial Number 437,- '7 filed on March19, 1930, now Patent No. 2,001,362; and U. S. PatentNo. 1,866,808 toIreland. The first mentioned patent shows the various details of thetoaster and the second ,pat-

ent fully discloses the timing mechanism.

In the operation of the toaster, a bread slice is placed upon thecarrier l0 while the same is in the uppermost position shown in Figurel. The handle id is then depressed, whereupon the carrier it is movedinto lowermost position and the bread is moved into toasting positionbetween the heating elements 8. In the course of the downward movementof the handle, a main switch l6 for the heating elements isautomaticallyv closed and when the carrier reaches lowermost position itis held therein by a catch member later released by the timingmechanism. Upon subsequent release of the catch member, the breadcarrier is moved into the uppermost end position of ejection orreception shown in Figure l by means of the spring 18 and leveragesystem generally designated at 2! whereupon the operator may remove thebread slice. During the upward movement of the bread carrier the mainswitch It for the electrical heating elements 8 is also opened in knownmanner.

The spring of the variable speed timing mechanism is Wound by means of arack 20 which is provided with a pin 22 engaged by a member 24 fixed ona slide 26 to which the handle I4 is attached. When the handle isdepressed" the lower surface of the member 24, which is preferably Vshaped, engages the pin 22 and pulls down the rack 20 thereby rotatingthe spring shaft 28 and energizing the spring '30 of thetiming'mechanism. As thespring unwinds it raises the rack 20 .therebyalso raising the slide 26 and member 24, the latter being provided withan uppe cam surface. which engages the catch for holding thebread-carrier in lowermost position to release the same after apredetermined amount of travel and thereby terminate the toasting of thebread slice. By varying the speed with which the spring unwinds andtheclock mechanism raises the rack 20, the time during which the breadcarrier holds the bread in position to be toasted betweenthe heatingelements and during which the heating elements are energized, may thusbe governed.

As the spring 30 unwinds, it rotates a shaft-32 having a cam 34 fixedthereon, by means of a gear-train generally designated at 36. The cam".34 operates within the forked end of an oscillater 40 which ispivotally mounted on a pin 4| and has one end attached to a balancewheel 42 by means of a spring 44,, By varying the positionof the pivotedoscillator 40 with respect to [the cam 34 and balance wheel 42,- thespeed of be varied. Figure 7 mechanism will operate at relatively greatspeed and it will require a relatively small amount of time for themember 24 associated with the operating handle to be raised by means ofa rack 28 from lowermost position into position to trip the catch forthe bread carrier. Figure 8 shows the parts so adjusted that the speedof the timing mechanism is reduced whereby a greater timeinterv'al isconsumed before the bread carrier is released.

It will be noted that variation of the position of pin 4| upon which theoscillator 40 is mounted, results in a variation of the the breadcarrier It holds a bread slice'wlthin are energized.

In the Ireland patents above referred to there are provided manual meansfor adjusting the position of the oscillator 40 so as to vary the speedof the timing mechanism. In accordance with the present invention,however, means are provided for automatically positioning the oscillator40 inaccordance with toaster temperature con,- ditions whereby the speedof the timing mechanism, and consequently the time interval during whichthe bread carrier is retained in lowermost position, will be caused tovary depending upon the prevailing conditions of temperature. That is tosay, the oscillator 40 is automatically moved in the direction of thecam 34 when the oven is cool whereby the bread carrier is retained inlowermost position within the oven for a relatively great amount of timeas previously explained. As the oven reaches higher temperatures theoscillator is automatically moved away from the cam 34 so that-the speedof the timing mechanism is3incre'ased .and the time interval duringwhich the carrier is retained in lowermost position for any giventoasting operation is correspondingly reduced. The speed of the variablespeed clock varies directly as the toaster tem-' perature and thetoasting intervals vary inversely. I

The means for automatically varying the position of oscillator 40 willnowbe described." These means include a thermobar generally designatedat 50 which is mounted is of substantially the same thickness andpossesses substantially the same cooling qualities as the base-member 4and the other sheet metal parts of the toaster. Preferably, the metallicsup port 52 is also of the same thickness as the sheet metal walls l2,l3, and l5'fo'rming the sides of the oven. The thermobar 50 has one endattached to the metallic strip 52 by means of a nut and bolt assembly 54and extends longitudinally of the toaster. As will be 'evident fromFigures 1 and 2, the thermobar 50 is fully exposed throughout its lengthto the oven draft or air currents entering through the openingsprovidedin the lower guard plate 56 of the toaster. Also, it is exposed to theradiant heat emanating from the heating element as will be evident fromFigures1and2.

The-thermobar 50 is composed of a first portion 60 which is secured tothe metallic support 52, and

time during .which i at one end upon a metallic strip 52 extendingtransversely across the bottom of the oven of the toaster; The metallicstrip 52 tionili of the thermobar tends to Warp upwardly 1 upon .beingheated whereas the portion 62 of the thermobar tends to warp downwardly,thus partially compensating for the movements of portion 69. If desireda straight continuous thermobar may be used in place of the compensatedone although the'latt'er is preferred.

A fulcrumed lever generally designated at 64 is pivotally connected to adown-turned lug 66 formed integrally with a plate 68 of spring steel.

clearly shown in- Figure 9 the upper horizontal with the variable speedclock.

surface of the base member 4 is provided with an opening 12 whichexposes the spring plate 68.

' In order to enable adjustment of the free end of the spring plate 68with respect to the base mem her 4 there is provided a rod or shaft 14which is journaled in a block Hi fixed to the upper surface of thebase'member '4. Secured to the rod 14 and opposite the opening 12 is acam 18 which passes through the opening 12 and engages the spring plate68. The rod l4 extends outside of the main casing 6 of the toaster andis provided with a knob by means'of which it may be manually rotated,whereupon the cam 18 will vary the position of the free end of springplate 68 and willconsequently vary the position of the lug 66 forminga'support for the fulcrumed lever 64. Any convenient means may beprovided for retaining the rod 14 in any selected position.

The free end of the arm 82 of thefulcrumed lever 64 is pivotallyconnected toa link 84 which in turn is pivoted to a bracket member 86fixed to the -.free end of portion 62 of the thermobar 50. The free endof arm 88 of the lever 84 is pivoted to a link 90 whose opposite end ispivoted to the arm 92 of a yoke'which also has a second arm 94. The arms92 and 94 are located on opposite sides of the timing mechanism and areboth fixed to a pin 98 which is journaled in and extends through thewalls 98 and mo of the timing mechanism. Fixed to the arm 98, whichforms part of the aforementioned yoke,'and extending through an openingformed in the wall Hill is the pin 4 I upon which the oscillator 40 ofthe timing mechanism is pivoted as previouslyexplained. In Fig. 10, 6aindicates an opening in the top of the casing 6 through which bread willbe inserted and through which the hot air passes freely upward throughthe toasting'chamber or oven.

In operation, a slice of bread is inserted'upon the bread carrier it]when it is in raised position I as shown in Figure 1. The handle it ismoved into lowermost position whereby the spring of the clock mechanismis wound and the bread carrier is retained in lowermost position bymeans'of a latchmechanism. Also, the energizing circuit for the toasterheating elements 8 ,is'closed. Assuming that the toaster is entirelycold, the thermobar 50 will be in the full line position shown in Figure1 with the result that the arm 92 of the supporting yoke for pin M willbe in raised full 1 amount by the timing mechanism to trip the latchwhich holds the bread carrier III in lowermost position. At the start ofthe operation the various parts will be in the positions above doscribedbut it will of course be understood that as the toaster becomes heated,the thermobar will become correspondingly hotter, and the pin 4|, willautomatically move the oscillator 40 further away from the cam 34,thereby increasing the speed of the timing mechanism. Thus, at the endof the toasting of the first slice, the speed of I the timing mechanismwill be greater than itwas at the beginning of the operation but theparts are sodesigned that the. average time, i. e. the time during whichthe bread carrier keeps the bread within the oven, is just-sufllcient totoast the bread slice the desiredlamount under the temperaturaconditionsprevailing in the oven. That is to say, the action of the thermostat iscorrelated with the regulating means provided If a second slice of breadis now inserted upon the bread carrier I0 before the oven is allowed tocool, the thermobar 50 will be somewhat heated and will be warped, forinstance into the dotted line position shown in Figure 1. In thisposition, the thermostat will operate by means of the link mechanism tohold oscillator 40 away from the cam 34 as preu'iously explained, andthe speed of the timing mechanism will be correspondingly increased withthe result that the bread carrier will hold the bread within the oven ashorter time than it did during the toasting of the first slice. Sincethe oven is at a higher temperature the bread will therefore be toastedto'the same degree as the first slice was toasted, even though it wasexposed to the heat for a shorter interval of time. With succeedingslices, the thermobar 50 will automatically regulate the timingmechanism so that the bread will be retained in the ovenan amount oftime depending upon the temperature conditions therein". Thus,completely uniform toast will be obtained irrespective of the startingconditions of temperature within the oven and irrespective of periods ofwaiting between the toasting of successive slices.

Assuming, for example, that three or four v slices have been toasted inrapid succession and. that the operator then waits several minutesbefore inserting the next slice, it will be seen that the thermobar 50will accurately respond By adjusting the knob an it is-possible toregulate the, toaster to produce toast having any *desired degree ofcrispness. If it is desired to produce toast that iswell done or dark,the knob 80 is manipulated in such direction that the cam 18 willoperate to allow the spring plate 68 to move closer to the base member4. As a result of such movement the fulcrumed lever 64 will be alsomoved in the saine direction and the pin 4! will consequently be movedin the direction of cam 34 thereby reducing the speed of the timingmechanism and increasing the time interval during which the bread slicesare retained in theoven. On the other hand, if it is desired to producelighter toast or toast which is less well done, the knob 80 ismanipulated in such a way as to cause cam 18 to move the free end ofspring plate 88 further away from the-base member}. Such movementresults in a moving of the pin ll carrying the oscillator as in adirection away from cam 36 with the result that the speed of the tim ingmechanism is increased and the time interval during which bread slicesare retained in the oven are correspondingly decreased. The toaster ispurely automatic and will operate to uniformly ventionconstitutes atoaster including electrical heating elements and wherein the toastingof the 7 bread slice is terminated both by turning off the heating meansand removing the bread slice therefrom, it will be understood that anydesired type of heating elements as for example, gas burners may beemployed and that it is further Within the purview of the invention thatany desired means may be associated with the thermally responsive deviceto control the toasting operation. To illustrate, the device may be usedto control the degree of heating of the element, or may operate toterminate the toasting operation by solely removing the bread slice fromthe heating element or solely rendering them inoperative as desired.Also, it is noted that those claims directed to an air draft orconvection currents are not intended to be limited to the specific typeof upright toaster hereshown but cover any type of toaster embodying thevarious claimed elements including a controlling thermostat exposed inconvection currents producedby the heating means irrespective of whethersuch currents represent themain draft as in the herein describedexample, or an auxiliary draft or air current.

I claim as my invention:

1. In an intermittently operated automatici toaster, heating means;means for supporting a bread slice in position to be toasted by saidheating means, controllable means for terminating the toasting of theslice, and a thermally responsive device controlling the operation ofthe ter. minating means, said device being fixedly secured with respectto the toaster and positioned so as to be removed from the bread sliceand subject to heat given ofi by said heating means, and also being solocated as to be exposed to a flow of air exerting a cooling actionthereon and which is continuously supplied to the toaster from outsidethereoi by convection currents resulting from the heat of said heatingmeans, said flow of air being operative to exert a cooling action uponthe thermally responsive device during cooling oi the heating elementsbetween successive toasting operations thereby to cause said thermallyresponsive device to closely follow oven temperature conditions of thespace occupied by the bread while being toasted and insure uniformtoasting of successive slices of bread in said toaster under allconditions.

2. In an upright automatic toaster, a casing provided with openings atthe bottom and top thereof permitting circulation of air therethrough,heating means in the casing, means for supporting a bread slice in thecasing in position to be toasted by said heating means, time controlledmeans for terminating the toasting of the slice, and a thermallyresponsive device removed from the bread slice and subject to heat givenoff by said heating means, and also exposed in a cooling vertical airdraft passing through. the

said omnings and created by the heat-given on? by said. heating means,said thermally responsive device controlling the time period provided'bysaid timecontrolled terminating means thereby to vary the toastinginterval in accordance with changes in its temperature.

3. In anautomatic toasmr, heating means a casing for the heating meansenclosing a toas ing spaced and provided with openings through which anair draft of appreciable size passing through the toasting space is setup by the heat ing means, means for supporting a bread slice beingtoasted by said heating means, a thermally responsive device mounted tobe traversed by said draft before it enters the toasting space andsubject to heat from the heating 'means, and controllable means forcontrolling the toasting of the bread slice, said last said means beingunder the control of said thermally responsive device.

in an automatic toaster, heating means, means for supporting a breadslice in position to be toasted by said heating means, a thermallyresponsive device freely exposed to the radiant heat given off by saidheating means and also freely exposed in an air draft created under theinfluence of heat from the heating means, and controllable means forterminating the toasting of the bread slice, said terminating meansbeing under the control of said thermally responsive de vice.

5. in an automatic toaster of the oven type, having an opening enablingcirculation oi therein from the outside thereof, heating meant. meansfor supporting a bread. slice in position to be toasted by said heatingmeans, controllable means for terminating the toasting of the slice byrendering the heating means inoperative, and a thermally responsivedevice removed from the bread slice and subject to heat givenoii" bysaid heating means, and also being so located as to exposed to anappreciable flow of air continuously supplied to the toaster from theoutside atnics=-- phere through said opening by convection duced by theheat of the heating means, said flow of air exerting a cooling actionupon the thermally responsive device during cooling of the heatingelements between successive toasting operations whereby the temperatureof said do vice more quickly follows changes in oven temperature, saidthermally responsive device controlling the operation of the terminatingmeans for every toasting operation to vary the toasting interval inaccordance with changes in its tem perature and insure substantiallyuniform toasting of successive slices oi bread in said toaster under allconditions.

6. In. an automatic toaster, heating means,

controllable means for moving-a bread slice to be toasted to and awayfrom. position to be toasted by said heating means, and a thermallyresponsive device subject to heat given of? by heating means and locatedin a cooling draft of air from outside the toaster set up by circula--tion induced by the heating means, said thermal ly responsive devicehaving a fixed connection with the toasterand controlling the operationof the bread moving means thereby to vary the toasting interval inaccordance with changes in its temperature and lllSlUE substantiallyuniform toasting of successive slices of bread in said toaster under allconditions.

' 'Z. In an automatic toaster, heating means, means for supporting abread slice in position to be toasted thereby, a timer, means con rolledby the timer for terminating the toasting of the bread slice, and athermostat fixedly secured with respect to the toaster and subject toheat from the heating means and also located in an air draft set upthereby, said thermostat controlling the time period provided by thetimer for every toasting operation thereby to vary the toasting intervalin accordance with changes in its tem- .an air draft created thereby forautomatically regulating the speed'of said clock.

9. In an automatic bread toaster having heating means, means forsupporting a bread slice being toasted by said heating means, athermostat exposed to the radiant heat given oiT' by the heating means,a variable speed clock, means connecting the thermally responsive deviceand variable speed clock for regulating the speed of the latter inaccordance with temperature fluctuations of the former, and meansassociated with said variable speed clock for terminating thetoasting ofthe bread slices.

10. An automatic toaster comprising heating means, means for moving abread slice into and away from position tobe toasted by said heatingmeans, a variable speed'clock controlling said .moving means, and athermally responsive device subject to heat given off by said heatingmeans and exposed in convection currents created thereby, said thermallyresponsive device being operatively connected to'said variable speedclock to regulate the same. v

11. An automatic toaster comprising heating means, means for moving abread slice into and away from position to be toasted by said heatingmeans, a variable speed clock controlling said moving means, and athermally responsive device exposed to radiant heat given off by saidheating means and also exposed in convection currents created thereby,said thermally responsive device being operatively connected to saidvariable speed clock to regulate the same.

.12. In an automatic toaster, heating means, means for supporting abread slice in position to be toasted by said heating means,controllable means for terminating the toasting of-the slice, and athermostat having one portion thereof adapted to warp in one directionand another portion adapted to warp in an opposite direction, saidthermostat being subject to heat given 011' by said heating means andexposed to a'cooling air draft created thereby, said thermostatcontrolling the operation of the terminating means thereby to vary thetoasting interval in accordance with changes in its temperature. 7

13. An automatic toaster comprising heating means, means for supportinga bread slice in position to be toasted by said heating means, means forterminating the toasting of said bread slice, a variable speed clockcontrolling said ter-' minatingmeans, and a thermally responsive devicesubject to heat given off by said heating means and also exposed inconvection currents created thereby, said thermally responsive devicebeing operatively-connected to said variable speed clock to regulate thesame.

14. In an' intermittently operated oven type automatic breadtoasteigheating means, means for supporting a bread slice being toastedby said heating means, means for terminating the toasting-of the breadslice, and a thermally responsive timing means controlling saidterminating means and thereby determining the duration of the toastinginterval, the temperature responsive portion of said timing means beingremoved from the bread slice'and subject to heat given off by saidheating means, and also being so located as to be-exposed to a flow ofair exerting a cooling action thereon andwhich is continuously suppliedto the toaster from the outside thereof by convection currents resultingfrom the heat of the heating means, said flow of air being operative toexert a cooling efiect 'upon said temperature responsive portion duringthe cooling of the heating elementsbetween successive toastingoperations thereby to cause the said temperature responsive portion toclosely follow oven temperature conditions and insure uniform toastingof successive slices of bread in said toaster unde all conditions.

15. In an automatic bread toaster, heating means, means for supporting abread slice being toasted by said heating means, a thermostat responsiveto the heatgiven oil by the heating means directly exposed to theradiant heat thereof and located in an air draft produced thereby,

a variable speed timing mechanism, means connecting said thermostat and'variable speed timing mechanismfor regulating the speed of the latterlnaccordance with temperature fluctuations of the former, and meansassociated with said variable speed timing mechanism for terminating thetoasting of the bread slice.

16. In an automatic toaster, heating means, means for supporting a breadslice in position to be toasted thereby, a timer for providing a timeperiod, means controlled ,by the timer for terminating the toasting ofthe bread slice, and a thermostat exposed to the radiant heat of theheating means and also located in an air draft set up thereby, saidthermostat controlling the time period provided by thetimer thereby tovary the toasting interval in accordance with changes in itstemperature.

17. In an automatic toaster, heating means, means for supporting a breadslice in position to be toasted by said heating means, a timer forproviding a time period, means controlled by the heating means and alsolocated in an air draft set up thereby, said air draft being operativeto cause the thermostat to closely follow the toaster temperature andcontrolling the time period provided by the timer thereby to vary thetoasting interval in accordance with changes in its temperature andinsure uniform toasting of succes-' sive bread slices in the toasterunder all conditions.

18. In an automatic toaster, heating means, means'for supporting a breadslice in position to be toasted by said heating means, a timer forproviding a time period, means controlled by the timer for terminatingthe toasting of the bread slice, a thermostat subject to heat fromthe.heat-' ing-means and also located in an airdraft set up thereby,said thermostat closely following the toaster temperature andcontrolling the time period provided by the timerthereby to vary thetoasting interval in accordance with changes in its temperature, andmeans for manually regulating said timer independently of saidthermostat.

19. In an automatic bread toaster having heating means, means forsupporting a'bread slice being toasted-by said heating means, athermally responsive device directly exposed to the radiant heat givenoff by the heating means, a variable speed clock, means connecting thethermally responsive device and variable speed clock for regulating thespeed of the latter in accordance with temperature fluctuations of theformer, means associated with said variable speed clock for terminatingthe toasting of the bread slices, and means for manually regulating thespeed of the variable speed clock independently of said thermostat.

20. An automatic toaster comprising heating means, means for supportinga bread slice in position to be toasted by said heating means, means forterminating the toasting of said bread slice, 2. variable speed clockcontrolling said terminating means, a thermally responsive devicesubject to heat given off by said heating means and also exposed inconvection currents created thereby, said thermally responsive devicebeing operatively connected to said variable speed clock to regulate thesame, and means for manually regulating the speed of said variable speedclock independently of said thermally responsive device.

21. A cooking device of the character described having a heating chambercomprising a cooking compartment, a variable speed clock mechanism fortiming the operation of said cooking device, and a thermally responsivemember positioned directly within said cooking compartment andoperatively connected with said clock mechanism for controlling thespeed thereof.

22. A cooking device comprising a cooking chamber, a timing meanscomprising a clock mechanism for timing the operation of said device,and a thermally responsive member for varying the time period providedby said timing means in accordance with the temperature afiecting the.said member, the said member being located in a position where it willbeaffected by the heat within the cooking chamber to substantially thesame degree or manner as the material being cooked therein.

23. A cooking device of the character described having a cooking chamberwithin which material is positioned to be cooked during the cookingoperation of said device, means comprising a timing device adapted toprovide a time period for saidoperation'and a thermally responsivemember adjacent to and spaced from said material; ,the said member beingsubject substantially to the'same heat and conditions afiecting the saidmaterial during a heating operation of said device and operativelyconnected with said timing device to automatically vary the length ofsaid time period. Y

24. In an automatic toaster, heating means, means for supporting a breadslice in position to be toasted by said heating means, a variable speedclock, means associated with said clock for automatically terminatingthe toasting of the bread slice, and means including a thermallyresponsive device removed from the bread and submeans for supporting abread slice in position to be toasted thereby, a timing mechanism, meanscontrolled by the timing-mechanism for terminating the toasting of thebread slide, and a thermostat exposed to the radiant heat of the heatingmeans, said thermostat controlling the operation of the timing mechanismthereby to vary the toasting interval changes in its temperature. 26,.In an automatic toaster, heating means, means for supporting a breadslice in position in accordance with to be toasted thereby, a timingmechanism, means I controlled by the timing mechanism for terminatingthe toasting of the bread slice, and a thermostat exposed to the radiantheat of the heating means, said thermostat controlling the operation ofthe timing mechanism thereby to vary the toasting interval in accordancewith changes in its temperature, and means for manually regulating saidtiming mechanism independently of said thermostat.

27. In an automatic toaster, heating elements spaced apart to provide aspace for bread being toasted, a casing for said heating elements havingopenings through which a main air draft having appreciable size andpassing through said bread toasting space is induced by the heat or theheating elements, and means for controlling the toasting of a breadslice in said bread toasting space including a thermally responsivemember removed from the bread slice and subject to the heat of theheating elements andposition to be traversed by said main air draft,said member being operative to insure substantially uniform toasting ofsuccessive slices of bread in said toaster.

28. An automatic toaster comprising heatin means, means for causing anappreciable amount of convection currents produced by the heat of theheating means to flow in a predetermined path, a timer for providing atime period, means operatively connected to the timer for terminating atoasting operation at the expiration of the time period, and meansincluding a thermally responsive member located in said path for varyingthe time period provided by said timer, said mema time period associatedwith said thermally responsive member and operatively connected to saidcontrolling means to institute operation thereof upon the expiration ofthe time period provided by the timer means, said casing having openingsto provide an air draft continuously re- 'plenished by outside air andpassing upwardly through said toasting space and said thermallyresponsive member being located so as to be traversed by said air draft,and said thermally responsive member being operative to vary the timeperiod provided by said timer means to insure substantially uniformtoasting of successive slices of bread in said toaster.

-30. In an automatic toaster, heating means,-

means for supporting a bread slicein position ,to be toasted thereby, atimingmechanism, means controlled by the timing mechanism forterminating the toasting of the bread slice, and a ther mostat exposedto the radiant heat of the heating means and likewise exposed toconvection .currents of appreciable size produced thereby and flowing ina predetermined path, said thermostat controlling the operation of thetiming mechanism thereby to vary the toasting interval in accordancewith changes in its temperature.

31. An automatic toaster comprising heating means, means for controllingatoasting operation,

10 a timer for controlling said toasting operation control means, and athermally responsive member operatively associated with said timer, to

control the time period provided thereby, said thermally responsivemember having two portions, one of which is movable to partiallycompensate for the movement of the other to thereby insure substantiallyuniform toasting of succes- 'sive slices of bread in said toaster.

MAURICE H. RAHAM. Y

